docs: def results_class_wise_metrics(self):
          """Class-wise metrics
  
          Returns
          -------
          dict
              results in a dictionary format
  
          """
  
          results = {}
          for tag_id, tag_label in enumerate(self.tag_label_list):
              if tag_label not in results:
                  results[tag_label] = {}
  
              # Counts
              results[tag_label]['count'] = {
                  'Nref': self.tag_wise[tag_label]['Nref'],
                  'Nsys': self.tag_wise[tag_label]['Nsys'],
                  'Ntp': self.tag_wise[tag_label]['Ntp'],
                  'Ntn': self.tag_wise[tag_label]['Ntn'],
                  'Nfp': self.tag_wise[tag_label]['Nfp'],
                  'Nfn': self.tag_wise[tag_label]['Nfn'],
              }
  
              # Equal error rate
              if self.y_pred_score[tag_label]:
                  results[tag_label]['eer'] = {
                      'eer': metric.equal_error_rate(
                          y_true=self.y_true[tag_label],
                          y_score=self.y_pred_score[tag_label]
                      )
                  }
  
              else:
                  results[tag_label]['eer'] = {
                      'eer': None
                  }
  
              # F-measure
              if self.tag_wise[tag_label]['Nref'] > 0:
  
                  precision = metric.precision(
                      Ntp=self.tag_wise[tag_label]['Ntp'],
                      Nsys=self.tag_wise[tag_label]['Nsys']
                  )
  
                  recall = metric.recall(
                      Ntp=self.tag_wise[tag_label]['Ntp'],
                      Nref=self.tag_wise[tag_label]['Nref']
                  )
  
                  f_measure = metric.f_measure(precision=precision, recall=recall)
  
              else:
                  precision = None
                  recall = None
                  f_measure = None
  
              results[tag_label]['f_measure'] = {
                  'f_measure': f_measure,
                  'precision': precision,
                  'recall': recall,
              }
  
          return results